Archimedes force of vacuum

One of the striking and longstanding problems of fundamental physics is the irreconcilability among the two main theories of last century, General Relativity and Quantum Theory. A manifestation of this tension is the value that quantum field theory attributes to the vacuum energy density, enormously larger than the value constrained from General Relativity by considering the radius of our universe. This problem, known as the cosmological constant problem [1], has been faced over the last decades with deep theoretical investigations, following also the evolution of the most important quantum gravity theories, like string theories, loop quantum gravity and many others [2–4]. None of the theoretical efforts has so far succeeded in finding a consensual solution, so that it is still questionable whether vacuum energy does interact with gravity, and what is its contribution to the cosmological constant [5, 6]. In spite of the common belief by the scientific community in the existence of an interaction between vacuum energy and gravity, not a single experimental test of this interaction exists. The activity of our group is devoted to perform the first experiment to verify or discharge the gravitational interaction of vacuum energy, by measuring the Archimedes force that the gravity exerts on a Casimir cavity. Our group has developed both the theory of the force and design the experiment/s that can be done to measure the effect.

To know more please read http://arxiv.org/abs/arXiv:1401.6940 or contact E. Calloni for the experimental part or G. Esposito, L. Rosa, for the theoretical part, or other members of the group.

To know more on cosmological constant problem and Vacuum Fluctuations interaction with Gravity:

[1] S. Weinberg: The cosmological constant problem. Rev. Mod. Phys. 61, 1 (1989).

[2] C. Rovelli, Quantum Gravity (Cambridge University Press, Cambridge, 2004).

[3] B. S. DeWitt and G. Esposito: An introduction to quantum gravity, Int. J. Geom Methods Mod. Phys.5101, (2008); G. Esposito, An introduction to quantum gravity, arXiv:1108.3269 [hep-th].

[4] E Bianchi, C Rovelli: "Is dark energy really a mystery?", Nature, 466(2010) 321

[5] T. Padmanabhan : Why does gravity ignore the vacuum energy? Int. J. Mod. Phys. D, 15, 2029 (2006).

Works of our group on Vacuum Fluctuations and phase transitions and Vacuum fluctuations and Gravity:

[1] E. Calloni, L. Di Fiore, G. Esposito, L. Milano, and L. Rosa: Vacuum fluctuation force on a rigid Casimir
cavity in a gravitational field. Phys. Lett. A 297 328 (2002).

[2] G. Bimonte, E. Calloni, G. Esposito, and L. Rosa: Energy-momentum tensor for a Casimir apparatus in a weak gravitational field. Phys. Rev. D 74, 085011 (2006); erratum Phys. Rev. D 75, 049904 (2007); erratum Phys. Rev. D 75, 089901 (2007), erratum Phys. Rev. D 77,109903 (2008).

[3] G. Bimonte, E. Calloni, G. Esposito, and L. Rosa: Relativistic mechanics of Casimir apparatuses in a weak gravitational field. Phys. Rev. D 76, 025008 (2007).

[4] G. Bimonte, E. Calloni, G. Esposito, L. Milano, and L. Rosa: Towards Measuring Variations of Casimir Energy by a Superconducting Cavity. Phys. Rev. Lett. 94, 180402 (2005).

[5] G. Bimonte, E. Calloni, G. Esposito, and L. Rosa: Variations of Casimir energy from a superconducting transition. Nucl. Phys. B 726, 441 (2005).

[6] G. Bimonte, D. Born, E. Calloni, G. Esposito, U. Huebner, E. Il'ichev, L. Rosa, F. Tafuri, and R. Vaglio: Low noise cryogenic system for the measurement of the Casimir energy in rigid cavities. J. Phys. A 41, 164023 (2008).

[7] A. Allocca, G. Bimonte, D. Born, E. Calloni, G. Esposito, U. Huebner, E. Il'ichev, L. Rosa, F. Tafuri: Results of Measuring the Influence of Casimir Energy on Superconducting Phase Transitions. Jour. Super and Novel Mag.25, 8, 2557 (2012).